William Legge 2nd Earl of DartmouthPC, FRS (20 June 1731 – 15 July 1801), styled as Viscount Lewisham from 1732 to 1750, was a Britishstatesman who is most remembered for his part in the government before and during the American Revolution.

In 1772, in correspondence with Sir William Johnson, the Superintendent of Northern Indian Affairs in America, he suggested there was no reasonable way the British Government could support new trade regulations with the Indians. He sympathised with Johnson's arguments but stated the Colonies did not seem inclined to concur with any new regulations.

Lord Dartmouth was a large donor to and the leading trustee for the English trust that would finance the establishment of the Moor's Charity School, in Lebanon, Connecticut by Eleazar Wheelock to educate and convert the Indians. Wheelock subsequently founded Dartmouth College in Hanover, New Hampshire, naming the school in Lord Dartmouth's honor in hopes of getting his financial support. Lord Dartmouth refused. In London, Lord Dartmouth supported the new Foundling Hospital, a charitable institution for the care and maintenance of London's abandoned children. He served as a vice president of the organization from 1755 until his death. The famous painter Sir Joshua Reynolds painted the Earl's portrait and donated it to the hospital. The portrait is still in the Foundling Hospital Collection and can be seen at the Foundling Museum in London. He was admitted a Fellow of the Royal Society on 7 November 1754.[2]

He died at Blackheath, Kent, on 15 July 1801, in the seventy-first year of his age, and was buried in Trinity Church in the Minories on 3 August 1801.[3] He was succeeded by his eldest son, George. Lady Dartmouth died in July 1805. The family lived at Sandwell Hall (since demolished) in the Sandwell Valley.